Induction-coil.



H. SHOEMAKER.

Patented July 9, I901.

IIIIIIIIIIII L.

oooooooo UNITED STATES PATENT Erica.

HARRY SHOEMAKER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GUSTAVE Pi GEHRING, OF SAME PLACE.

lNDUCTlON COlL.

sPEctrroA'rIoN forming part of Letters Patent No. 678,047, dated July 9, 1901. Application filed April 16, 19U1. seen no. tense. on model.)

To cLZZ whom it may concern.-

Be it known that I, HARRY SHO MAKER', a citizen of the United States, residing at Phila delphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Induction- Ooils,of which the following is a specification.

My invention relates to improvements in induction-coils; and the main object of my invention is the provision of a coil whose magnetic circuit is made as short as possible and yet make it complete with the exception of an air-gap of very small reluctance.

Another object of my invention is the provision of an ind uction-coil which is very simple and inexpensive in construction and is therefore thoroughly efficient and practical in use.

To attain the desired objects, my invention consists of an induction-coil embodying novel features of construction and combination of parts,substantially as disclosed herein.

In the drawings, Figure 1 is a longitudinal section taken on line :0 as of Fig. 2. Fig. 2 is a section taken on liney y of Fig. 1, and Fig. 3 is a plan View of one of the annealed disks.

Referring to the drawings, A designates a wooden section, which, with the other wooden section B when tied together by the brass bolts 0, forms a spool D, provided with a circular opening or core E. Fitting upon the spool and separated by the paper disks F are the thin annealed sheets or disks G of steel, which are provided with the gaps or spaces H, as shown in Fig. 3. Upon each side of these disks and fitting upon the core of the spool are the series of cup-shaped disks J, bent so as to form the magnetic circuit, with the small air-gap K between their inner edges, as shown in Fig. 1. Placed around the outer edges of the disk G is an insulation L, around which is wound the primary coil M, which is also insulated from the secondary coil N, said coils being in the space between the edges of the disk G and the bent ends of the disks J It will thus be seen that the magnetic circuit being short and having an air-gap of small reluctance it allows the changing of the strength of magnetism to take place much quicker than with a long magnetic circuit, hence inducing in the secondary coils strong currents more accurate and prompt than could be produced with coils of longer magnetic circuits, the air-gap in each individual disk end and the paper between them stopping all eddy-currents through the core.

It is evident that I provide a very simple, durable,and inexpensiveinduction coil which will perform its functions in a thorough and satisfactory manner.

I claim- 1. An induction-coil, comprising a central non-conducting core or spool, a series of metal disks fitting upon said spool and provided with air-gaps between their ends, cup-shaped either end of the disks and having an air-gap between their edges, and a secondary and a primary coil mounted upon the disks in the space between them in the bent ends of the cup-shaped disks.

' 2. An induction-coil, comprisinga non-conducting spool, a series of disks provided with an air-gap, and a series of cup-shaped disks provided with an air-gap surrounding said spool, and primary and secondary coils surrounding the series of disks.

3. An induction-coil consisting of a nonconducting base, a series of thin metal disks, having an air-ga p between their ends, sheets of paper fitting between the disks, a series of cup-shaped disks upon the base on each side of the other disks and primary and secondary windings surrounding the disks in the casing formed by the cup-shaped portion of the other disks.

In testimony whereof I affix my signature in presence of two witnesses.

, HARRY SHOEMAKER.

Witnesses:

M. WIEGAND, J. N. FORT, .Ir.

metal'disks surrounding said spool upon 

